Investigators in the Urologic Oncology Branch of the National Cancer Institute are the urologic surgeons and general urology consultants to the entire National Institutes of Health. In this role we see patients in consultation for all pediatric and adult urologic surgical problems. The Urologic Oncology Branch answers all emergency, as well as elective urologic surgical consultations and provides 24 hour coverage for urologic surgical emergencies that may arise in the Clinical Center Hospital. Increasing surgery in AIDS patients is being performed. The Urologic Oncology Branch also collaborates in the procurement of tissue for studies required by other investigative units. The degree of involvement of the Urologic Oncology Branch in the planning and execution of these studies is variable. The Urologic Oncology Branch often plays an instrumental role in the design of these studies while in other collaborations, the Urologic Surgical Service merely provides tissue. Approximately 30% of the clinical surgical effort of the Urologic Oncology Branch is devoted to these consultative and collaborative studies.